Method and apparatus for making potable water

ABSTRACT

Impure water is made suitable for drinking in an apparatus comprising a pressurizable holding tank attached to a purification cartridge containing an impurities adsorbent and a fine filter. A gas-containing cartridge is pierced to provide a bactericidal gas for killing pathogenic microorganisms and for pressurizing the holding tank to force the water through the purification cartridge.

United States Patent [1 1 Gartner METHOD AND APPARATUS FOR MAKINGPOTABLE WATER [75] Inventor: William Joseph Gartner, Bartlett, Ill.

[73] Assignee: Gartner Research & Development Co., Bartlett, Ill.

[22] Filed: Apr. 13, 1972 [21] Appl. N0.: 243,645

[52] US. Cl 210/205, 210/220, 210/266,

|5l Int. Cl 801d 27/02 [58] Field of Search 210/205, 221, 266;

[56] References Cited UNITED STATES PATENTS 3,327,859 6/1967 Pall210/282 6/1967 Reynolds et al. 222/5 3/1969 Sanzebacher 210/266 PrimaryExaminerSamih N. Zahama Assistant Examiner-Benoit Castel Att0rney-MaxDressler et al.

[5 7 ABSTRACT Impure water is made suitable for drinking in an apparatuscomprising a pressurizable holding tank attached to a purificationcartridge containing an impurities adsorbent and a fine filter. Agas-containing cartridge is pierced to provide a bactericidal gas forkilling pathogenic microorganisms and for pressurizing the holding tankto force the water through the purification cartridge.

9 Claims, 1 Drawing Figure METHOD AND APPARATUS FOR MAKING POTABLE WATERBRIEF DESCRIPTION OF THE INVENTION There is a need for a light, compactsystem capable of converting small quantities of impure water to potablewater. Hikers, campers, fishermen and other outdoorsmen are frequentlyin places where drinking water is unavailable although water of impurequality is present. Soldiers, on maneuvers or in combat, have need for asystem for water purification. In lifeboats, a suitable system forconverting sea water to potable water may make the difference betweensurvival and non-survival.

For raw water of relatively good purity in which bacterial contaminationis the principal problem, there are chemical-containing tablets whichmay be added to the water to kill the bacteria. Such tablets, however,are ineffective in the removal of many water contaminants such asminerals, suspended particles and odorcontaining materials. In fact,such tablets usually add an odor or taste of their own, making the waterunpleasant to drink.

In accordance with the present invention, there is provided an apparatusfor making potable water from contaminated water comprising apressurizable holding tank having a water retention space superposed bya gas retention space, an outlet conduit leading from a lower portion ofsaid holding tank to a purification cartridge containing a granularadsorbent, valve means in said conduit means, gas cartridge meanscontaining a gas under pressure, means to puncture said gas cartridgemeans to release the gas therefrom and conduit means to transfer saidreleased gas to a lower portion of said water retention space.

DETAILED DESCRIPTION OF THE INVENTION The drawing shows the system ofthis invention in elevation and partly in section.

The drawing shows outer casing 11 in which the other elements of thesystem are contained. Outer casing II has a hinged front panel (notshown in the drawing) for ready access to the interior elements.

Holding tank 12, molded of polyethylene or other suitable plasticmaterial, is a vessel capable of withstanding internal pressure of theorder of about 20 pounds per square inch. The tank has generallyrectangular corners and is L-shaped in that its upper wall is of steppedconstruction and includes upper portion 13, vertical wall 14 and lowerportion 16. This construction provides air space 17 below upper portion13 when the tank is filled with water through opening 18 and to itslevel. The opening is sealed by stopper 19 which fits tightly in theopening.

pressurizing cylinder 21 is attached to vertical wall 14 by threadedconnection 22, the male portion of which is an integral part of theholding tank molding. Tube 23 extends through threaded connection 22 atits upper end and to a position at its lower end and close to the bottomof the holding tank. Beyond the threaded connection, tube 23 is flared,as shown at 24, to receive the puncturable end of gas capsule 26 and tomake a gas tight connection therewith.

Threaded plunger 27 fits into the open end of pres surizing cylinder 21and, when threaded far enough into the pressurizing cylinder, pushes gascapsule 26 into point 28 to puncture the puncturable end of the capsuleand thereby release its contents to pass into and through tube 23 to thebottom of the holding tank and the water contained therein.

Gas capsule 26 contains gas for decontaminating and pressurizing thewater. The gas comprises a mixture of nitrous oxide and chlorine, theformer predominating. In a specific embodiment, the gas capsule contains8 grams of gas of which 0.025 grams is chlorine and 7.975 grams innitrous oxide.

Conduit 29, connected to the lower part of holding tank 12, leads to thelower part of purification cartridge 31 when valve 32 is opened.Cartridge 31, shown partly in section, contains granular adsorbent 32and fine outlet filter 33, the latter having sufficient resistance toflow to provide substantial back pressure within the filter cartridgewhen water flows therethrough. Preferably, fine outlet filter 33 is ofsuch fineness as to provide a back pressure from about 5 to about 20pounds per square inch when water at ambient temperature flows throughthe cartridge at the rate of 5 gallons per hour per square inch of areaof filter 33. Preferably, cartridge 31 also contains a fine inlet filter(not shown) having a resistance to flow at least as great as that ofoutlet filter 33. A detailed description of a preferred filter cartridgeutilizable in this invention is shown in my copending application Ser.No. 243,644, filed concurrently herewith, the disclosure of saidapplication being incorporated herein by reference.

Granular adsorbent 32 may be made of activated carbon when intended topurify water containing gases, or odor or color-forming materials. Whenthe cartridge is intended to treat waters of high mineral content, suchas brackish water or sea water, granular adsorbent 32 may be an ionexchange resin, and preferably a mixture of anionic and cationicexchange resins.

It is usually desired to remove from the water most of the chlorineadded from the gas cartridge because its taste is unpleasant. Inaddition, the passage of water through an ion exchange resin tends toimpart an unpleasant taste thereto. For these reasons, the granularadsorbent 32 is usually not an ion exchange resin in its entirety. Forthe adsorption of minerals, it is usually preferred to utilize acartridge containing one or more ion exchange resins as a principalconstituent occupying a major portion of the cartridge space, and alsocontaining a layer of activated carbon at each end of the cartridge toremove chlorine and the unpleasant ion exchange resin taste from thewater.

Cartridge 31 is held in place by clamps 34. The effluent from thecartridge is withdrawn through conduit 36 and collected in a suitableclean receptacle for drinking.

In operation, cap 19 is removed, the holding tank is filled with thewater to be made potable up to the level of opening 18, and the cap isthen firmly replaced. During this period, valve 32 is closed so that thewater in the holding tank remains in place. If the water containsvisible silt or coarse suspended matter, it may be fil tered out byutilizing a funnel and filter when filling the tank through the opening.

Threaded plunger 27 is then removed from the pressurizing cylinder topermit gas cartridge 26 to be placed therein; and the plunger is thenreplaced. As the plunger continues to be threaded inwardly, it forcesthe puncturable end of the gas cartridge into point 28, puncturing thecartridge and releasing the gas to flow into and through line 23. Thegas emerging from the bottom of line 23 bubbles through the water, sothat there is intimate contact between the water and the gas and thechlorine content of the gas can exercise its bactericidal action on thewater.

The nitrous oxide content of the gas is the principal pressurizingcomponent thereof and exerts pressure on the water from gas space [7. Ina holding tank having a capacity for liquid of about one-half gallon anda gas holding capacity of about 20 cubic inches, the 8 gram gascartridge provides an initial pressure of about 20 pounds per squareinch at a temperature of 75 F.

After the gas cartridge is punctured, valve 32 is permitted to remainclosed for a waiting period of about seconds. It is then opened topermit the water to flow upwardly through the purification cartridge.The resistance of the fine filters at the entrance and exit of thefilter cartridge limits flow therethrough to a moderate rate, rangingfrom about gallons per hour at the beginning of the flow when the gaspressure is about 20 psi and gradually reducing to about 3 gallons perhour as the outflow of water expands the gas space and reduces thepressure to about 4 psi.

A test of this invention was made with a deliberately contaminated watermade from raw municipal sewage to which salts had been added to bringthe minerals content up to a level of 1,000 ppm. One-half gallon of thisliquid was treated in the apparatus described above utilizing apurification cartridge in which the granular adsorbent was primarily ionexchange resin, but which contained a layer of activated carbon at eachend of the cartridge. The effluent water had less than 20 ppm ofdissolved solids and no chlorine. The colifom count was reduced from 4(on a scale ranging from O to 5) to zero, the upper limit for potabilitybeing less than 1. The effluent water was fit to drink and had nounpleasant taste, odor or color.

While the invention has been described with respect to a particularmodification, it is to be understood that variation may be made withoutdeparting from the essence of this invention. The chlorine concentrationin the gas mixture in the cartridge may vary, for example, from about0.] percent to about I percent by volume, depending on how much of afactor of safety is desired to assume the completness of thebactericidal action.

Also, if desired, other gas systems may be used in place of thechlorine-nitrous oxide system described above. Ozone, for example, hasboth a bactericidal action and a high vapor pressure and may be used inthe gas capsule.

Other modifications and variations will be apparent to those skilled inthe art.

I claim:

I. Apparatus for making potable water from contaminated water comprisinga pressurizable holding tank having a water retention space superposedby a gas retention space, an outlet conduit leading from a lower portionof said holding tank to a purification cartridge containing a granularadsorbent, valve means in said outlet conduit, gas cartridge meanscontaining a gas under pressure, means to puncture said gas cartridgemeans to release the gas therefrom and conduit means communicating withsaid cartridge and a lower portion of said water retention space totransfer the released gas to said lower portion of said water retentionspace.

2. The apparatus of claim 1 wherein said purification cartridge isvertically disposed and said outlet is connected to the lower portion ofsaid purification cartridge.

3. The apparatus of claim 2 wherein said purification cartridge has anoutlet filter of such fineness as to provide a back pressure within thecartridge from about 5 to about 20 pounds per square inch when water atambient temperatures flows through the cartridge at the rate of 5gallons per hour per square inch of area of said outlet filter.

4. The apparatus of claim 3 wherein said purification cartridge has aninlet filter having at least as much flow resistance as said outletfilter.

5. The apparatus of claim 1 wherein said tank is L- shaped and said gasretention space is in the upper portion of the vertical member of the L.

6. The apparatus of claim 1 wherein said granular adsorbent comprisesactivated carbon as at least the predominant constituent thereof.

7. The apparatus of claim 1 wherein said granular adsorbent comprises atleast one ion exchange resin as at least the predominant constituentthereof.

8. The apparatus of claim 1 wherein said gas under pressure comprises amixture of a major proportion of nitrous oxide and a minor proportion ofchlorine.

9. Apparatus for making potable water from contaminated water comprisingan L-shaped pressurizable holding tank having a water retention spacecorresponding to the horizontal member of the L and a gas retentionspace corresponding to the upper portion of the vertical member of theL, an outlet conduit leading from a lower portion of said holding tankto a lower portion of a vertically disposed purification cartridgecontaining a granular adsorbent and having an outlet filter valve meansin said conduit means, gas cartridge means containing under pressure amixture of a major proportion of nitrous oxide and a minor proportion ofchlorine, means to puncture said gas cartridge, means to release the gastherefrom and conduit means communicating with said cartridge and alower portion of said water retention space to transfer the released gasto said lower portion of said water retention space.

* l k k 1

1. Apparatus for making potable water from contaminated water comprisinga pressurizable holding tank having a water retention space superposedby a gas retention space, an outlet conduit leading from a lower portionof said holding tank to a purification cartridge containing a granularadsorbent, valve means in said outlet conduit, gas cartridge meanscontaining a gas under pressure, means to puncture said gas cartridgemeans to release the gas therefrom and conduit means communicating withsaid cartridge and a lower portion of said water retention space totransfer the released gas to said lower portion of said water retentionspace.
 2. The apparatus of claim 1 wherein said purification cartridgeis vertically disposed and said outlet is connected to the lower portionof said purification cartridge.
 3. The apparatus of claim 2 wherein saidpurification cartridge has an outlet filter of such fineness as toprovide a back pressure within the cartridge from about 5 to about 20pounds per square inch when water at ambient temperatures flows throughthe cartridge at the rate of 5 gallons per hour per square inch of areaof said outlet filter.
 4. The apparatus of claim 3 wherein saidpurification cartridge has an inlet filter having at least as much flowresistance as said outlet filter.
 5. The apparatus of claim 1 whereinsaid tank is L-shaped and said gas retention space is in the upperportion of the vertical member of the L.
 6. The apparatus of claim 1wherein said granular adsorbent comprises activated carbon as at leastthe predominant constituent thereof.
 7. The apparatus of claim 1 whereinsaid granular adsorbent comprises at least one ion exchange resin as atleast the predominant constituent thereof.
 8. The apparatus of claim 1wherein said gas under pressure comprises a mixture of a majorproportion of nitrous oxide and a minor proportion of chlorine. 9.Apparatus for making potable water from contaminated water comprising anL-shaped pressurizable holding tank having a water retention spacecorresponding to the horizontal member of the L and a gas retentionspace corresponding to the upper portion of the vertical member of theL, an outlet conduit leading from a lower portion of said holding tankto a lower portion of a vertically disposed purification cartridgecontaining a granular adsorbent and having an outlet filter valve meansin said conduit means, gas cartridge means containing under pressure amixture of a major proportion of nitrous oxide and a minor proportion ofchlorine, means to puncture said gas cartridge, means to release the gastherefrom and conduit means communicating with said cartridge and alower portion of said water retention space to transfer the released gasto said lower portion of said water retention space.